A heat cycle grain drying tower

Abstract

The utility model provides a kind of thermal cycle grain drying tower, including tower skeleton and outer wall insulation board;Outer wall insulation board is enclosed drying tower to tower skeleton cladding formed;The inside two sides of tower skeleton and outer wall insulation board form hot air channel and cold air channel respectively, and the channel between cold air channel and hot air channel is bunker channel;Bunker channel top is equipped with inlet, bottom is equipped with stop valve;The bottom of tower skeleton is equipped with scraper, scraper corresponds with bunker channel, for the grain in bunker channel discharge is sent;The bottom of tower skeleton is also equipped with lower fan and combustion machine, lower fan connects hot air channel and cold air channel;Combustion machine is arranged in hot air channel side, for providing hot air to hot air channel;Hot air can enter cold air channel through bunker channel;The top of cold air channel is equipped with upper fan, for discharging air.The utility model greatly improves thermal energy utilization efficiency, reduces the energy consumption of combustion machine, saves operating cost.

Description

Technical Field

[0001] This utility model belongs to the field of grain drying, and in particular relates to a heat circulation grain drying tower. Background Technology

[0002] In the post-harvest processing of grain, grain drying is one of the key processes for ensuring grain quality and preventing mold and loss. Traditional grain drying equipment mostly uses single-channel direct-flow or simple hot air circulation systems, which suffer from problems such as low heat energy utilization, low drying efficiency, and uneven temperature distribution. Especially in large-scale grain drying processes, because the hot air cannot fully contact the grain, some grains are underheated or overheated, which not only affects the drying effect but may also cause a decline in grain quality, such as scorching, cracking, and nutrient loss.

[0003] Furthermore, existing drying towers have a relatively simple structural design, with an unreasonable layout of hot air and material channels. Hot air often passes through once and is directly discharged, failing to achieve efficient heat recovery and reuse, resulting in energy waste and high operating costs. At the same time, traditional equipment lacks effective means to control hot air velocity, temperature uniformity, and material residence time, making it difficult to meet the precise drying needs of different types of grains with different moisture contents. Utility Model Content

[0004] In view of this, the present invention aims to propose a heat circulation grain drying tower, which achieves full contact between hot air and grain and recycling of heat by optimizing the tower structure, setting up hot air and cold air channels in layers, and scientifically arranging ventilation and heating components, thus having significant technological progress and practical value.

[0005] To achieve the above objectives, the technical solution of this utility model is implemented as follows: A heat-circulating grain drying tower includes a tower frame and an external wall insulation panel; the external wall insulation panel covers the tower frame to form a closed drying tower. Hot air channels and cold air channels are formed between the inner sides of the tower frame and the outer wall insulation board, respectively. The space between the cold air channels and the hot air channels is a material silo channel. The top of the material silo channel is equipped with a material inlet and the bottom is equipped with a shut-off valve. The bottom of the tower frame is equipped with a scraper conveyor, which corresponds to the silo channel and is used to transport the grain discharged from the silo channel. The bottom of the tower frame is also equipped with a down fan and a burner, and the down fan is connected to the hot air channel and the cold air channel; The burner is located on one side of the hot air duct and is used to supply hot air to the hot air duct; the hot air can enter the cold air duct through the hopper duct; An upper fan is installed at the top of the cold air duct to exhaust air.

[0006] Furthermore, the tower frame is composed of 7 layers of tower groups, namely the first tower group, the second tower group, the third tower group, the fourth tower group, the fifth tower group, the sixth tower group and the seventh tower group; The middle section of the first material tower group is the installation section, which is equipped with a scraper conveyor and a downdraft fan; the two sides are the hot air section and the cold air section, respectively, with the burner installed in the hot air section. The middle section of the second to seventh material tower groups is a ventilation section, with air inlet and air outlet sections on both sides respectively. The ventilation section of 6 material tower groups and 1 installation section are combined to form a material silo channel; the air inlet section of 6 material tower groups and 1 hot air section are combined to form a hot air channel; the air outlet section of 6 material tower groups and 1 cold air section are combined to form a cold air channel.

[0007] Furthermore, the ventilation sections of the six material tower groups are interconnected, and the ventilation sections are composed of several ventilation layers; The ventilation layer includes a first ventilation panel, a second ventilation panel, two side panels, and several corner panels; the first ventilation panel, the second ventilation panel, and the two side panels are connected end to end, and several corner panels arranged in a row are arranged between the first ventilation panel and the second ventilation panel, with a gap between every two adjacent corner panels. Both ventilation panels No. 1 and No. 2 are equipped with several ventilation holes; the corner plate has an inverted V-shaped cross-section, and the ventilation holes correspond to the corner plate. The ventilation holes are divided into large ventilation holes and small ventilation holes; The No. 1 ventilation plate is equipped with large ventilation holes, and the No. 2 ventilation plate is equipped with small ventilation holes at the positions corresponding to the large ventilation holes. That is, the two ends of the corner plate are respectively equipped with large ventilation holes and small ventilation holes. This ventilation layer is used as a drying layer. Small ventilation holes are set in ventilation plate No. 1, and small ventilation holes are also set in ventilation plate No. 2 at the corresponding positions. That is, small ventilation holes are set at both ends of the corner plate. This ventilation layer is set as a thawing layer.

[0008] Furthermore, each ventilation layer is provided with one or two rows of corner plates. If there are two rows of corner plates, the upper and lower corner plates of each two rows are staggered. The drying layer has two corner plates. A large ventilation hole is set above the No. 1 ventilation plate and a small ventilation hole is set below it. A small ventilation hole is set at the position corresponding to the large ventilation hole of the No. 2 ventilation plate and a large ventilation hole is set at the position corresponding to the small ventilation hole. Furthermore, the tower frame has three tempering layers, interspersed among several drying layers. The tempering layers are located in the upper middle section, middle section, and lower middle section of the tower frame, respectively. The drying layer above the middle and upper sections is the high-temperature section, the drying layer between the middle and upper sections and the middle section is the medium-temperature section, the drying layer between the middle section and the middle and lower sections is the low-temperature section, and the drying layer below the middle and lower sections is the cooling section.

[0009] Furthermore, the air outlet structures of the second to seventh material tower groups are identical; The air inlets of the second, third, and fourth material tower groups are equipped with baffles to divide the hot air passage of the material tower group into two sections; the section near the middle is the hot air passage A, and the other section is the hot air passage B; the hot air rises through the hot air passage B to the fifth material tower group without baffles, where part of the hot air continues to rise and part of the hot air enters the hot air passage A. The third, fourth, and fifth material tower groups are equipped with perforated plates at the bottom of the hot air B channel.

[0010] Furthermore, the second and third material tower groups are equipped with flap assemblies at the top of the hot air A channel. The flap assemblies can partially block the cross section of the hot air A channel, thereby controlling the flow rate.

[0011] Compared with existing technologies, the thermal circulation grain drying tower of this utility model has the following advantages: (1) The heat circulation grain drying tower described in this utility model is provided with independent hot air channel and cold air channel. After the hot air passes through the silo channel and fully exchanges heat with the grain, it enters the cold air channel and is finally discharged by the upper fan or partially recovered and reused, which greatly improves the heat energy utilization efficiency, reduces the energy consumption of the burner, and saves operating costs.

[0012] (2) The heat circulation grain drying tower of this utility model adopts a structure of ventilation plate, side plate and inverted V-shaped corner plate in the ventilation layer. Multiple small drying layers are formed between the corner plates, and the ventilation holes are arranged in correspondence with the drying layers, which is conducive to the directional flow and uniform distribution of hot air, enhances the heat exchange efficiency between hot air and grain, and improves the drying effect.

[0013] (3) The heat circulation grain drying tower described in this utility model realizes continuous grain conveying through the scraper conveyor set at the bottom. With the reasonable feeding, drying and discharging structure, it can realize continuous grain drying operation, which is suitable for large-scale grain processing scenarios and improves overall operation efficiency and production continuity. Attached Figure Description

[0014] The accompanying drawings, which form part of this utility model, are used to provide a further understanding of the utility model. The illustrative embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute an undue limitation of the utility model. In the drawings: Figure 1 This is a schematic diagram of an explosion of a thermal circulation grain drying tower according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the first material tower assembly according to an embodiment of the present utility model; Figure 3This is a schematic diagram of the second material tower assembly according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the third feed tower assembly according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the fourth feed tower group according to an embodiment of the present utility model; Figure 6 This is a schematic diagram of the fifth material tower group according to an embodiment of the present utility model; Figure 7 This is a schematic diagram of the sixth material tower group according to an embodiment of the present utility model; Figure 8 This is a schematic diagram of the seventh material tower group according to an embodiment of the present utility model; Figure 9 This is a schematic diagram of the explosion of the thawing layer of the ventilation layer described in this embodiment of the present invention; Figure 10 This is a schematic diagram of the explosion of the drying layer of the ventilation layer according to an embodiment of the present invention; Figure 11 This is a schematic diagram illustrating the working principle of a heat circulation grain drying tower according to an embodiment of the present invention. Figure 12 This is a schematic diagram of the flap assembly described in an embodiment of the present utility model; Figure 13 This is a schematic diagram showing the positions of the drying layer and tempering layer in the tower frame according to an embodiment of the present invention; Figure 14 This is a schematic diagram of the hot air flow between adjacent drying layers as described in an embodiment of the present invention.

[0015] Explanation of reference numerals in the attached figures: 1. Tower frame; 101. High temperature section; 102. Medium temperature section; 103. Low temperature section; 104. Cooling section; 105. Tempering section; 11. First tower group; 12. Second tower group; 13. Third tower group; 14. Fourth tower group; 15. Fifth tower group; 16. Sixth tower group; 17. Seventh tower group; 18. Ventilation layer; 1811. Ventilation plate No. 1; 1812. Ventilation plate No. 2; 182. Side plate; 183. Corner plate; 1841. Large ventilation hole; 1842. Small ventilation hole; 19. Partition plate; 110. Mesh plate; 111. Flip plate assembly; 2. External wall insulation board; 3. Hot air passage; 4. Cold air passage; 5. Material silo passage; 6. Scraper conveyor; 7. Burner; 8. Downward fan; 9. Upward fan. Detailed Implementation

[0016] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0017] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0018] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0019] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0020] A type of heat-circulating grain drying tower, such as Figure 1 As shown, the structure includes a tower frame 1 and an external wall insulation panel 2. The external wall insulation panel 2 covers the tower frame 1 to form a closed drying tower. The closed coverage of the tower frame 1 by the external wall insulation panel 2 can effectively reduce heat exchange between the inside and outside of the drying tower. During the drying process, the heat carried by the hot air is not easily lost to the outside through the tower wall, which reduces energy consumption and allows the hot air to be used more efficiently for grain drying. Hot air channel 3 and cold air channel 4 are formed between the inner two sides of the tower frame 1 and the outer wall insulation board 2, respectively. The space between the cold air channel 4 and the hot air channel 3 is the material hopper channel 5. The top of the material hopper channel 5 is equipped with a material inlet and the bottom is equipped with a shut-off valve. The bottom of the tower frame 1 is equipped with a scraper conveyor 6, which corresponds to the hopper channel 5 and is used to transport the grain discharged from the hopper channel 5. The bottom of the tower frame 1 is also provided with a down fan 8 and a burner 7, and the down fan 8 is connected to the hot air channel 3 and the cold air channel 4; The burner 7 is located on one side of the hot air duct 3 and is used to supply hot air to the hot air duct 3; the hot air can enter the cold air duct 4 through the hopper duct 5; the top of the cold air duct 4 is equipped with an upper fan 9 for exhausting air.

[0021] Preferred, such as Figures 2-8 As shown, the tower frame 1 is composed of 7 layers of material tower groups, namely the first material tower group 11, the second material tower group 12, the third material tower group 13, the fourth material tower group 14, the fifth material tower group 15, the sixth material tower group 16 and the seventh material tower group 17. The middle part of the first material tower group 11 is the installation section, which is equipped with a scraper conveyor 6 and a downdraft fan 8; the two sides are the hot air section and the cold air section, respectively, and the hot air section is equipped with a burner 7; The middle section of the second material tower group 12 to the seventh material tower group 17 is a ventilation section, and the two sides are the air inlet section and the air outlet section, respectively. The ventilation section of 6 material tower groups and 1 installation section are combined to form the material silo channel 5; the air inlet section of 6 material tower groups and 1 hot air section are combined to form the hot air channel 3; the air outlet section of 6 material tower groups and 1 cold air section are combined to form the cold air channel 4.

[0022] Preferably, the ventilation sections of the six material tower groups are interconnected, and the ventilation sections are composed of several ventilation layers 18; like Figure 9 Figure 10 As shown, the ventilation layer 18 includes a first ventilation panel 1811, a second ventilation panel 1812, two side panels 182, and several corner panels 183; the first ventilation panel 1811, the second ventilation panel 1812, and the two side panels 182 are connected end to end, and several corner panels 183 arranged in rows are disposed between the first ventilation panel 1811 and the second ventilation panel 1812, with a gap between every two adjacent corner panels 183. Both ventilation plate 1811 and ventilation plate 1812 are provided with several ventilation holes; the corner plate 183 has an inverted V-shaped cross section, and the ventilation holes correspond to the corner plate 183. The ventilation holes are divided into large ventilation holes 1841 and small ventilation holes 1842; from Figure 9 Figure 10 As can be seen, comparing the two clearly distinguishes their sizes; The first ventilation plate 1811 is provided with a large ventilation hole 1841, and the second ventilation plate 1812 is provided with a small ventilation hole 1842 at the position corresponding to the large ventilation hole 1841. That is, the two ends of the corner plate 183 are respectively corresponding to the large ventilation hole 1841 and the small ventilation hole 1842. The ventilation layer 18 with this configuration serves as a drying layer. The first ventilation plate 1811 is provided with small ventilation holes 1842, and the second ventilation plate 1812 is also provided with small ventilation holes 1842 at the corresponding positions. That is, both ends of the corner plate 183 are provided with small ventilation holes 1842. This ventilation layer 18 is set as a thawing layer.

[0023] Preferably, each ventilation layer 18 is provided with one or two rows of corner plates 183. If there are two rows of corner plates 183, the upper and lower corner plates 183 in each two rows are staggered. The drying layer has two corner plates 183. A large ventilation hole 1841 is provided above the first ventilation plate 1811 and a small ventilation hole 1842 is provided below it. A small ventilation hole 1842 is provided at the position corresponding to the large ventilation hole 1841 on the second ventilation plate 1812, and a large ventilation hole 1841 is provided at the position corresponding to the small ventilation hole 1842. Compared to traditional straight-cylinder drying methods, this design aims to increase the pressure of hot air, allowing it to penetrate the grain and exit through the large ventilation holes 1841 on the opposite side, significantly increasing the airflow in contact with the grain; for example... Figure 14 As shown; Preferably, the tower frame 1 has three tempering layers, which are interspersed among several drying layers. The tempering layers are located in the upper middle section, middle section, and lower middle section of the tower frame 1, respectively. like Figure 13 As shown, the drying layer above the middle and upper sections is the high-temperature section 101, the drying layer between the middle and upper sections and the middle section is the medium-temperature section 102, the drying layer between the middle section and the middle and lower sections is the low-temperature section 103, and the drying layer below the middle and lower sections is the cooling section 104.

[0024] Grain is a material containing both internal and external moisture. While the outer layer of moisture evaporates easily, the internal moisture takes time to migrate outwards. If grain is continuously exposed to high-temperature hot air for rapid drying, it can lead to: an overly dry surface (even cracking and splitting), while the internal moisture remains high, resulting in incomplete drying; and a decline in grain quality after drying, affecting its storability and processing performance. The role of the tempering layer is to pause or slow down the direct heating of the hot air after the grain has been dried at high temperature, giving the grain's internal moisture time to migrate to the surface. This achieves a drying process of "rapidly dehydrating the surface first, and then slowly equalizing the interior," improving the overall uniformity of drying, reducing the moisture gradient between the inside and outside of the grain, reducing the breakage rate, and improving the quality of the grain.

[0025] Preferably, the air outlet structures of the second to seventh material tower groups 17 are the same; The air inlets of the second material tower group 12, the third material tower group 13 and the fourth material tower group 14 are equipped with baffles 19, which divide the hot air channel 3 of the material tower group into two sections; the section near the middle is the hot air channel A, and the other section is the hot air channel B; the hot air rises through the hot air channel B and reaches the fifth material tower group 15 without baffles 19, where part of the hot air continues to rise and part of the hot air enters the hot air channel A. The third material tower group 13, the fourth material tower group 14 and the fifth material tower group 15 are equipped with perforated plates 110 at the bottom of the hot air B channel. By setting the perforated plates 110, the purpose of uniform airflow and increased heat melting can be achieved.

[0026] Preferably, the second feed tower group 12 and the third feed tower group 13 are equipped with a flap assembly 111 at the top of the hot air A channel. The flap assembly 111 can partially block the cross-section of the hot air A channel, thereby achieving the purpose of controlling the flow rate. Figure 11 As shown, the flap assembly 111 is a conventional mechanical structure, which works in conjunction with a traction motor, traction pulley, and traction rope. The flap is hinged to the material tower assembly. One end of the traction rope is connected to the flap, and the other end is connected to the traction motor through the traction pulley, achieving the purpose of opening and closing the flap. Pulling the traction rope upward indicates that the flap is closed, and releasing the traction rope downward indicates that the flap is open. Because the mechanical structure of the flap assembly is a conventional mechanical structure, it will not be described in detail. Figure 12 As shown; The flap assembly 111 can flexibly adjust the hot air supply according to different stages of grain drying, which can ensure the drying effect, save energy, and avoid over-drying.

[0027] Working principle, such as Figure 11 As shown, the burner 7 located on one side of the hot air channel 3 is ignited and puts the heat generated by fuel combustion into the hot air channel 3; at this time, the hot air channel 3 is filled with high-temperature hot air; the down fan 8 at the bottom of the tower frame 1 starts, which provides power for the flow of hot air in the hot air channel 3 on the one hand, and also draws in some air in the cold air channel 4 to participate in the circulation on the other hand; when the down fan 8 is running, it will push the hot air to flow upward along the hot air channel 3, allowing the hot air to gradually pass through the hot air section of each material tower group, and finally enter the material hopper channel 5; The hot air entering the silo channel 5 from the hot air channel 3 will come into contact with the grain to be dried in the silo channel 5 to complete the drying operation of the grain; the grain passes through the ventilation layer 18 (drying layer and tempering layer) with different temperatures and functions from top to bottom, and goes through the process of "high temperature rapid dehydration → medium and low temperature tempering and equalization → low temperature stable drying → final cooling". The tempering layer pauses or reduces the direct blowing of hot air, allowing sufficient time for the internal moisture of the grain to migrate to the surface, thereby improving the uniformity of drying and the quality of the grain. The air inlets of the second, third, and fourth feed tower groups are equipped with baffles 19, which divide the hot air channel 3 into hot air channel A and hot air channel B. Some of the hot air will first enter the hot air channel B and flow upwards, and then flow to the fifth feed tower group 15 without baffles 19, where it will split into two paths - one path continues to rise along the hot air channel B, and the other path turns back and enters the hot air channel A. This design allows the hot air to come into contact with the grain and exchange heat multiple times in different sections, and can also use "multi-stage diversion" to regulate the overall air temperature. The third, fourth and fifth material tower groups are equipped with perforated plates 110 at the bottom of the hot air B channel. When the hot air passes through the perforated plates 110, it will be dispersed to achieve a uniform airflow effect and further improve the drying consistency. Hot air cools down as it passes through ventilation layer 18, becoming cold air that enters cold air duct 4. Part of it is discharged upward through upper fan 9, and part of it is discharged downward through lower fan 8 and re-enters hot air duct 3 to complete the cycle. The tower is equipped with a humidity detector. When the required drying effect is achieved, the shut-off valve at the bottom of the hopper channel 5 is opened. The grain in the hopper channel 5 will fall onto the scraper conveyor 6 below under the action of gravity. After the scraper conveyor 6 is started, it will transport the fallen grain to the next process through its own scraper chain and other conveying structures.

[0028] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A heat-circulating grain drying tower, characterized in that: It includes the tower frame and the external wall insulation board; the external wall insulation board covers the tower frame to form a closed drying tower; Hot air channels and cold air channels are formed between the inner sides of the tower frame and the outer wall insulation board, respectively. The space between the cold air channels and the hot air channels is a material silo channel. The top of the material silo channel is equipped with a material inlet and the bottom is equipped with a shut-off valve. The bottom of the tower frame is equipped with a scraper conveyor, which corresponds to the silo channel and is used to transport the grain discharged from the silo channel. The bottom of the tower frame is also equipped with a down fan and a burner, and the down fan is connected to the hot air channel and the cold air channel; The burner is located on one side of the hot air duct and is used to supply hot air to the hot air duct; the hot air can enter the cold air duct through the hopper duct; An upper fan is installed at the top of the cold air duct to exhaust air.

2. The heat circulation grain drying tower according to claim 1, characterized in that: The tower frame is composed of 7 layers of material tower groups, namely the first material tower group, the second material tower group, the third material tower group, the fourth material tower group, the fifth material tower group, the sixth material tower group and the seventh material tower group; The middle section of the first material tower group is the installation section, which is equipped with a scraper conveyor and a downdraft fan; the two sides are the hot air section and the cold air section, respectively, with the burner installed in the hot air section. The middle section of the second to seventh material tower groups is a ventilation section, with air inlet and air outlet sections on both sides respectively. The ventilation section of 6 material tower groups and 1 installation section are combined to form a material silo channel; the air inlet section of 6 material tower groups and 1 hot air section are combined to form a hot air channel; the air outlet section of 6 material tower groups and 1 cold air section are combined to form a cold air channel.

3. The heat circulation grain drying tower according to claim 2, characterized in that: The ventilation sections of the six material tower groups are interconnected, and the ventilation sections are composed of several ventilation layers; The ventilation layer includes a first ventilation panel, a second ventilation panel, two side panels, and several corner panels; the first ventilation panel, the second ventilation panel, and the two side panels are connected end to end, and several corner panels arranged in a row are arranged between the first ventilation panel and the second ventilation panel, with a gap between every two adjacent corner panels. Both ventilation panels No. 1 and No. 2 are equipped with several ventilation holes; the corner plate has an inverted V-shaped cross-section, and the ventilation holes correspond to the corner plate. The ventilation holes are divided into large ventilation holes and small ventilation holes; The No. 1 ventilation plate is equipped with large ventilation holes, and the No. 2 ventilation plate is equipped with small ventilation holes at the positions corresponding to the large ventilation holes. That is, the two ends of the corner plate are respectively equipped with large ventilation holes and small ventilation holes. This ventilation layer is used as a drying layer. Small ventilation holes are set in ventilation plate No. 1, and small ventilation holes are also set in ventilation plate No. 2 at the corresponding positions. That is, small ventilation holes are set at both ends of the corner plate. This ventilation layer is set as a thawing layer.

4. The heat circulation grain drying tower according to claim 3, characterized in that: Each ventilation layer is equipped with one or two rows of corner plates. If there are two rows of corner plates, the upper and lower corner plates of each two rows are staggered. The drying layer has two corner plates. A large ventilation hole is set above the No. 1 ventilation plate and a small ventilation hole is set below it. A small ventilation hole is set at the position corresponding to the large ventilation hole of the No. 2 ventilation plate, and a large ventilation hole is set at the position corresponding to the small ventilation hole.

5. A heat-circulating grain drying tower according to claim 4, characterized in that: The tower frame has three tempering layers, interspersed among several drying layers. The tempering layers are located in the upper middle section, middle section, and lower middle section of the tower frame, respectively. The drying layer above the middle and upper sections is the high-temperature section, the drying layer between the middle and upper sections and the middle section is the medium-temperature section, the drying layer between the middle section and the middle and lower sections is the low-temperature section, and the drying layer below the middle and lower sections is the cooling section.

6. A heat-circulating grain drying tower according to claim 2, characterized in that: The air outlet structures of the second to seventh material tower groups are the same; The air inlets of the second, third, and fourth material tower groups are equipped with baffles to divide the hot air passage of the material tower group into two sections; the section near the middle is the hot air passage A, and the other section is the hot air passage B; the hot air rises through the hot air passage B to the fifth material tower group without baffles, where part of the hot air continues to rise and part of the hot air enters the hot air passage A. The third, fourth, and fifth material tower groups are equipped with perforated plates at the bottom of the hot air B channel.

7. A heat-circulating grain drying tower according to claim 6, characterized in that: The second and third feed tower groups are equipped with flap assemblies at the top of the hot air A channel. The flap assemblies can partially block the cross section of the hot air A channel, thereby controlling the flow rate.

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